Reduction in glucocorticoid receptors in renal biopsies of patients with lupus nephritis

Objectives: The first-line treatment for lupus nephritis is the administration of glucocorticoids (GC) that mediate their effects via the glucocorticoid receptor (GR). The aim of this study was to investigate the expression of GR protein in the cortical area of renal parenchyma of normal and diseased renal biopsies from treated and untreated patients. Design and methods: The immunohistochemical EnVision/HRP technique was performed on renal tissue to detect GR protein. Statistical analysis was performed by SAS (2001). Results: The antigen was mainly detected in glomerular podocytes and in tubules. The number of GR-positive podocytes of the controls was significantly higher than in the untreated patients, which was accordingly higher than in patients who were under medication. Conclusions: The lower number of GR-positive cells in the diseased kidney compared to controls is possibly linked to tissue-specific GC resistance, whereas the decreased GR expression in podocytes of treated compared to untreated patients may be due to a down-regulation effect after GCs' administration. © 2007 The Canadian Society of Clinical Chemists